what is living ?, characterisics of living organism, Nomenclature,Rules of Nomenclature, Systematics,Identification,ICBN,ICZN, Taxonomy,Tools of taxonomy

1. Class - +2 1st yr sc
ZOOLOGY
Chapter 1
The living world
By Rasmita Sahoo
M.phil in zoology

2. What is living ?
•Living means
having life or
being alive.
•Something that
can carry out
some essential
features.
•Living things are
made up of cells and
can carry out cellular
activities.

3. CHARACTERISTI
CS OF LIVING
ORGANISMS
1. Growth
2. Reproduction
3. Metabolism
4. Cellular organization
5. Consciousness

4. GROWTH• Growth is usually defined by the increase in mass
and number of individual organisms.
• Humans visibly grow up to a certain age but the
cells keep on dividing and thus new cells in the
body keep on replacing the old ones.
• Some of the nonliving things also seem to grow in
size due to the accumulation of particles, for
example
– the growth of a mountain. Living
things grow due to cell division.
• Thus, growth is not a defining character.

5. Reproduction
• It is the process by which an organism
produces an individual like its own.
• Reproduction is of two types- sexual and
asexual reproduction.
• Most of the mammals like humans
reproduce by sexual reproduction.
• But when we consider unicellular organisms
like bacteria, growth and reproduction
become ambiguous as both results from the
division of the cell.
• Thus, reproduction can’t be a essential for
living.

6. Metabolism
• It comprises all the
chemical reactions going
inside a living cell or
body.
• Thus, it is a typical
characteristic of living
beings.
• Nonliving things do not
show metabolism.

7. Cellular Organization
• Organisms are typically
made up of cells.
• Cells form tissues,
tissues form organs,
organs form organ
system and organ
system form organism.

8. Consciousness
• It is a property by the virtue of
which an organism reacts to an
external stimulus or change in
environment.
• It is a typical property of
living organisms.
• They have the ability to sense
any change in their environment.

9. Criteria that Determine What Is Living ?
• A living thing is able to maintain the internal environment of the body.
This is known as homeostasis.
• The structure of a living thing is highly organized.
• It should be able to breakdownor build-up nutrients
to carry out the metabolic activities.
• It should have the ability to adaptto changing
environmental conditions.
• It should have the ability to respond to external stimuli.
• It should be able to increase in size and mass.

10. 1. Digestive system is ------- type of process.
2. Photosynthesis is ----------- type process.
3. --------- level of organisation seen in
annelida.
4. In plants growth period is -----------
5. In animals growth period is --------

11. 6. Nature choose which type of reproduction as
suitable ?
7. Which type of reproduction does not show
variation.
8. --------- type of cell division found in Asexual
reproduction.
9. ---------- type of reproduction show variation .
10. What are the criteria to determine living and
nonliving ?

12. 05-05-
2020
Dr Heena
Devnani
3
3